Well,apart for clearance I can't see why the difference.Bear in mind,if you use longer shocks at the front when the car was designed for short shocks it will limit uptravel.Other thing why shorter front shocks are the norm may be that massive front droop is not needed,I mean,every off road car since the RC10 has more rear droop than front.
You can shock balance using Fred's technique with different lenght shocks,just need to take shock leverage into account,then it's (rate of spring + leverage) X weight bias to balance because all it matters is where the spring is mounted in relation to the wheel to achieve front-rear spring harmony and not equal travel.

Okay so I am trying this with my 22, Red spring front, Yellow rear.
Using 120fps gopro footage the front and rear seem to rise at the same rate but the front quickly settles were the rear keeps going up and down for a couple more cycles. Is this balanced or I am way off?

Out of curiosity, and a desire to arrive at a better driving buggy, I checked the spring balance on my RC8.2e. I'm running the kit springs, and it turns out that the front was too stiff with the shocks set up the way I've been running it. However, I was able to get it balance by changing the shock positions, in effect softening the front a lot and stiffening the rear a bit.

Knowing that I would now need to do something with the roll centers, I went ahead and lowered the rear roll center a bit since I now have more wheel rate. I haven't had a chance to put it on a track yet, but I did a little testing today in dirt/gravel/grass. It really feels a lot more responsive but also more predictable so far. I'm really anxious to see how it jumps now, because it previously was a little inconsistent and sometimes like to fly nose high too easily.

Good stuff in here.

I would think if rebound is the same ur really close ur oil selection should take care of the reverberation. Make sure to keep ur oils balanced in feel not actual weight front 2 rear.
Being way different shock angles and travel

Page 6. Post #80

Thanks, and sorry I knew I read it somewhere but couldn't find it again.

Is there an instructional video on how to get a balanced suspension?

I think I understand the basic principle, but when I go to apply it to my b4, the rear end keeps bouncing up and down the springs after I drop it from a 4inch test height. This is due to the extra weight out back right?

I currently have #2 pistons, green springs in back, brown up front, with silver rear springs as an option. I set the preload collars to the ride height I want.

Anyone have any thoughts?

You don't actually need to drop it. You can just push down both ends and watch the rate at which they come back up. I found balance with my B4 with Kyosho orange in the front and Kyosho yellow in back. I had a ballast weight in the back and 1/4 oz in each rear triangle. I had the battery all the way to the back. You're basically watching to see how quickly the chassis springs back up. Any other movement is not critical.

Wow I am really late to the party. This has to be one of the greatest threads on rc ever. Thank you Fred and thank all of you for passing on your unabated and sincere knowledge so we may bask in a little of your Zen. I feel the urge to stick a 'Tune With Camber Links' sticker on my car. I don't and can't pretend to fully understand what's going on here but I fully intend to refer back at a later stage in my rc 'career' when my mind is more prepared. That's how we learn right?

I have a layman question to help me better understand roll stiffness. I'll use 2wd buggy as front is soley for steering and rear is traction.

If I increase front roll stiffness, are my tires biting more (vertically) into the ground therefore inducing more steering? Or if I decrease front roll stiffness, my outside tire has more force over it (compared to inner tire) therefore increasing steering? As I understand, the outside tire plays more importance in steering(?)

For the rear, if I increase roll stiffness, do I get more forward traction? If I decrease roll stiffness, do I get more side traction, and less forward traction?

Using the broom analogy, more roll resistance means more force on the tire right? And if we use the correct shock oils, springs, pack, the tires will in theory have more force acting onto the ground with a high roll resistance (not skimming over bumps etc)? And thus the tires being more utilized, in terms of steering and (forward) traction.

Am I making sense or am I late for my pills?

All things being equal, decreasing the front roll stiffness will decrease understeer/increase oversteer. Increasing front roll stiffness will increase understeer/decrease oversteer.

The opposite is true at the back. Increasing roll stiffness will increase oversteer/decrease understeer while decreasing roll stiffness will increase understeer/decrease oversteer.

This is what I have found with my mid motored Cougar. The weight balance of the car is close to 33/67. In the front I am running 3 hole pistons with 25wt oil and in the rear I've got 5 hole pistons with 35wt oil. The piston sizes are pretty close to the kit setup for the car only I have switched the oil weights around (kit is 4 hole 35wt front, 6 hole 30wt rear). I have always questioned myself when using the lighter front oil as there is not a single setup I have seen yet that uses lighter oil in the front.

At my track there are some rough and rocky sections and watching he car, it always looked as though the rear of the car was pivoting on the front wheels. I noticed that as I went thicker and thicker in the rear, it was controlling the pivoting action a lot better until I got the point where my oils were equal front and rear but it was starting to get a bit stiff for the rest of the track (I was up to 40wt rear by now but finding the rear tires were starting to bounce off the bumps). I thought screw it, lets see what happens with thin oil in the front as I couldn't keep making the back stiffer. Straight away it started getting better. After I found the right "ratio" of oil weight front/rear, I was able to bring the rear back down to 30wt without losing any control over the rough bits.

I've stated before that I run older vintage style buggies. I do have a newer car but it's more of a project. All of my cars are 2wd. I recently got my JRX-Pro SE tuned quite well. On the outdoor dirt track (which is what the car was originally designed around) here it'll hang with anything else. Not so much on the hard packed blue groove clay track here though but that's more of a durability issue as it just can't take a wrong landing as well as the tougher new cars. The tuning I've done to this car is consistent with my other buggies though and relevant to new vehicles as well.

I run an equal amount of droop front to rear. My total suspension travel is always equal at each end. Since the front shocks are mounted further inwards than the rear, the front shocks have less travel which is why they are shorter. If I was running the same shock pistons front to rear, the shock pack would not be equal front to rear since the piston speed per amount of wheel travel up front is slower than the rear. This means that the front shocks will have less pack per wheel travel even though the pistons are the same. The speed of the shock oil through the front pistons is always going to be slower.

Since I run an equal amount of suspension travel front to rear, it's easy to see how much shock travel I have at each end. I took the total shock travel at the front and divided it by the total travel at the rear. I'm talking about shock travel only measured at the shock shaft. Not wheel travel. I ended up with about 75% of the total travel in front as the rear. Since I didn't want to end up trying to calculate piston speeds I took a different approach and said that whatever the total area of the piston holes I had in the rear, I wanted something close to 75% of the total hole area in the front shocks. I have always liked #55 orange pistons in Losi rear shocks. I originally started running them in 1992 when Losi drivers used them. Back then I copied driver's setup sheets too.

Losi offers pistons with hole sizes ranging from a #53 hole size up to a #60. It's easy to look up a drill size chart to see what diameter each hole is. All of those standard bore Losi pistons have 3 holes in them too so using this information I made a simple chart showing the total hole area of each piston.
Since I decided to start with a #55 piston in the rear and wanted roughly 75% of that total area up front, all I needed to do was look at the chart. A 3 hole #55 piston has a total hole area of .006368 sq in. Since all of them are .00 something, I drop those 2 digits on the chart so I use 6368. A #56 piston is 5092, a #57 is 4354, and so forth and so on. When I divide 5092 (#56 piston) by 6368 (#55 piston) we can see that it (#56) is 79.9% of the total piston hole area of a #55 piston. I started there and installed a #56 piston in the front shocks. I also needed to run lighter oil up front. I ended up running 30W in the rear and 20W up front to balance. The car now passes the level drop test with oil installed.

How does it drive? Fantastic. On our off road track it is very forgiving. It's funny to see kids wonder how a car that is much older than they are can handle so well compared to theirs. Mine is tuned. Theirs isn't. It's that simple. Total potential of each vehicle is another matter altogether. If I need more or less pack anywhere, I'll change pistons at both ends. Losi was kind enough to offer many piston choices and the new big bore shocks out there also have many options. If I decide to go up to a #56 piston in back, I'll also go to a #58 up front and change oils accordingly.

Associated standard bore shocks are another thing altogether. They offer 3 piston choices. All 3 of them are 2 hole. A #1 is a #54 hole, a #2 piston is a #55 hole, and a #3 piston is a #56 hole. They also offer a blank piston so you can drill your own and in my opinion this is a must have. Using their 3 available sizes I run a #1 in the rear and a #3 up front. It works quite well but I need to play with my own sizes to improve on them or just go to big bores.

Anyways, play around with this as a guideline and see how you like it. I'm still tweaking the technique a little bit but this is a fantastic starting point to build off of. It is working quite well for me. I'm still playing though to account for weight difference at each end and not only shock travel so I may yet revise this.

I drilled some 3 hole pistons for my SC10FT- 3 x #60. Using 35f/32.5r AE oils. Just drilled a pair of 3 x #57 to try in the rear. My local indoor track has a couple jumps where you can catch some air (@3-4 feet). It really helps keep your momentum smooth if you can down side them. Track is high bite & smooth.


Here is a video of 2wd mod-
http://www.youtube.com/watch?v=llIZW...=results_video

Hideeho
I'm going to have a full day at the track Saturday (9a-8p), so I will give this a try. Everything else you have presented has worked exceptionaly well, but this is the 1st thing that has really flown in the face of what everyone else is doing. I plan on rebalancing the springs (I've made a few minor changes w/o doing it), setting the travel & then will work on the pistons on Saturday. Everything else has worked, & I see the logic behind this, so I'll let you know how it goes.

I can't guarantee that you'll like it (or dislike it). I only present the techniques and logic that I use so others can see if it works for them too and to get people thinking in terms of what various changes make to handling.